Threshold defect production in silicon determined by density functional theory molecular dynamics simulations

We studied threshold displacement energies for creating stable Frenkel pairs in silicon using density functional theory molecular dynamics simulations. The average threshold energy over all lattice directions was found to be 36 +/- 2(ST AT)+/- 2(SY ST) eV, and thresholds in the directions < 100 > and < 111 > were found to be 20 +/- 2(SY ST) eV and 12.5 +/- 1.5(SY ST) eV, respectively. Moreover, we found that in most studied lattice directions, a bond defect complex is formed with a lower threshold than a Frenkel pair. The average threshold energy for producing either a bond defect or a Frenkel pair was found to be 24 +/- 1(ST AT)+/- 2(SY ST) eV.